From 526df4f52a07a02687dd43ceb752621a41883f95 Mon Sep 17 00:00:00 2001
From: Bhasker Hariharan <bhaskerh@google.com>
Date: Fri, 5 Jun 2020 13:41:19 -0700
Subject: Fix error code returned due to Port exhaustion.

For TCP sockets gVisor incorrectly returns EAGAIN when no ephemeral ports are
available to bind during a connect. Linux returns EADDRNOTAVAIL. This change
fixes gVisor to return the correct code and adds a test for the same.

This change also fixes a minor bug for ping sockets where connect() would fail
with EINVAL unless the socket was bound first.

Also added tests for testing UDP Port exhaustion and Ping socket port
exhaustion.

PiperOrigin-RevId: 314988525
---
 pkg/sentry/socket/netstack/BUILD       | 1 +
 pkg/sentry/socket/netstack/netstack.go | 9 +++++++++
 pkg/tcpip/transport/icmp/endpoint.go   | 1 +
 3 files changed, 11 insertions(+)

(limited to 'pkg')

diff --git a/pkg/sentry/socket/netstack/BUILD b/pkg/sentry/socket/netstack/BUILD
index 333e0042e..8f0f5466e 100644
--- a/pkg/sentry/socket/netstack/BUILD
+++ b/pkg/sentry/socket/netstack/BUILD
@@ -50,5 +50,6 @@ go_library(
         "//pkg/tcpip/transport/udp",
         "//pkg/usermem",
         "//pkg/waiter",
+        "@org_golang_x_sys//unix:go_default_library",
     ],
 )
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index 60df51dae..e1e0c5931 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -33,6 +33,7 @@ import (
 	"syscall"
 	"time"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/amutex"
 	"gvisor.dev/gvisor/pkg/binary"
@@ -719,6 +720,14 @@ func (s *socketOpsCommon) Connect(t *kernel.Task, sockaddr []byte, blocking bool
 	defer s.EventUnregister(&e)
 
 	if err := s.Endpoint.Connect(addr); err != tcpip.ErrConnectStarted && err != tcpip.ErrAlreadyConnecting {
+		if (s.family == unix.AF_INET || s.family == unix.AF_INET6) && s.skType == linux.SOCK_STREAM {
+			// TCP unlike UDP returns EADDRNOTAVAIL when it can't
+			// find an available local ephemeral port.
+			if err == tcpip.ErrNoPortAvailable {
+				return syserr.ErrAddressNotAvailable
+			}
+		}
+
 		return syserr.TranslateNetstackError(err)
 	}
 
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 3bc72bc19..57e0a069b 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -506,6 +506,7 @@ func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 	nicID := addr.NIC
 	localPort := uint16(0)
 	switch e.state {
+	case stateInitial:
 	case stateBound, stateConnected:
 		localPort = e.ID.LocalPort
 		if e.BindNICID == 0 {
-- 
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